Part Number: DLP3000
I am a Msc student at Structured light Laboratory, University of the Witwatersrand, South Africa. We are working on an experiment that uses DMD (DLP3000) with flash pumped Nd:YAG laser with an output power of 2.3mW. The DMD was working perfectly as a reflecting mirror (the device not connected to the power supply). As soon we started modulating it, i.e. connected the device to the power supply, and set all mirrors to the off- state, it experienced a huge damage by the laser (Please see attached images).
We do not understand why this had happened and we are still confused about Section 6.4 of DLP3000 DLP 0.3 WVGA Series 220 DMD datasheet (Rev. B) - "Recommended operating conditions" where the maximum illumination for wavelengths of greater than 700 nm is given as 10mW/cm^2. We were definitely not close to this power damage threshold.
Currently, we are suppose to continue the experiment with another DMD, but before that we would like to understand the reasons for this damage so as we avoid it in our experiment?
We would also like to understand:
- If the thresholds is the same for all of the DMD states, for example if the threshold is the same in the sleep-mode(not connected to power) and in on-state (when mirrors are at angles of 12 degrees).
- If this threshold is for the average or the peak power?
- The filling factor in the sleep-mode is around 92%. What is the filling factor for the device in the on-state?
- Transmission for the window on the micro-mirrors for wavelength 1.64 micrometers is around 78%, so the losses from this window is 22%. What is the percentage of light that got reflected and the percentage got absorbed by the window?
- What is the power threshold for the silicon substrate under the micro-mirrors?
We greatly appreciate if you can help us to have full understand on how this damage happened. Thank you in advance.
